Specific-gravity-determining apparatus



Oct. 11, 1927.

G. B. LINDERMAN, JR

SPECIFIC GRAVITY DETERMINING APPARATUS Filed May 27, 1924 ATTORN E\Y Patented ct. l1,

GARRETTB. LINDERMN, JR., 0F BETHLEHEM, PENNSYLVANIA, ASSIGNOR, BY MESNE ASSIGNMENTS, T AMERICAN METER COMPANY, 0F NEW YORK, Y., A CORPORA- Tron or DELAWARE.

SPECIFIC-GRAVITYPDETEING APPARATUS.

Application letbMay 27, 1924. Serial No. 716,223.

My invention relates to apparatus for determining the speciic gravity ofv fluids, and it has for an object to provide a device of this character which shall operate dynamically upon a fluid whose specic gravity is to be determined and upon a fluid of reference in order to develop pressures whose difference is utilized to determine the ratio of the densities of the fluids.

More particularly, my invention has for an obj ectto provide apparatus of the character referred to, which incorporates a pair of blowers, one blower being supplied with air, and thel other blower being supplied with I5 gas, the supply of air and of gas being under equal pressures, together with means associated with the outlet connections of the blowers for determining the specific gravity of the gas with respect to the air. A further object of my invention is to provide a pair of blowers whose rotors are operated in a predetermined speed relation, v and which are supplied with gas and air respectively at equal pressures, together with manometric devices associated with the outlet connections of the blowers, the manometric devices each having a leg exposed to the same pressure, and the'latter legs containing logarithmic floats, whereby the ratio w of the mass per unit volume of gas with respect to the mass per unit volume of air may be ascertained? V Apparatus made in accordance with my invention is illustrated in the accompanyingv drawings, forming a part of this application,

in which:

Figure 1 is a diagrammatic view of my improved specific gravity determining appa= ratus, and i Figure 2, a longitudinal section of a portion of the apparatus illustrating` circulation orice means.

Referring now to the drawing ,more in detail for a better understanding of my invention, I show a gas main 10 having associated therewith specific gravity determining appa- Y ratus, at 11, which determines the specific gravity' of the gas flowingthrough the main f `10 with respect to air. l The specific gravity determining apparatus at 11, includes a gas blower 12 and an air blower 13 having casings 14 and 15 and rotors 16 and 17, respectively, the rotors 16 and 17 being driven in predetermined speed blower 13, and to relation, preferably synchronously, for exe5 ample, I show the rotors 16 and 17 carried by thesame rotor shaft 18. f

The gas blower 12 is provided with an inlet connection 20 which communicates centrally with respect to the casing 14 and with @0 the gas main l0. The casing 1.5 of the airj blower 13 is provided with an air inlet cn\ nection 21. In order that air supplied to the air blower 13 shall be under the same pressure as gas supplied to the gas blower 12, I provide pressure equalizing means be# tween the supply connections 20 and 21. To this end, the air supply connection 21, preferably communicates with a chamber 22 which is provided with a connection 23 leading tothe gas main 10. Air is supplied to the chamber 22 throughv a small inlet connection 24, such connection being associated with any suitable means for securing a small f flow of air into the chamber 22,'the object l@ being merely to supply sutlicient air into the chamber 22 to prevent the How of gas therein through the connection 23. The inflow of air is so controlled that the pressure of air in the chamber 22 will be equal to thatof the -gas in the main 10.

The gas blower 12 andathe'air blower 13 are provided, respectively, with outlet connect10nsf25 and 26 communicating with the leg portions 27 and 28 of the manometric 35 devices 29 and 30, respectively. The manometric devices 29 and 30 are partially filled with any suitable fluid and the legs 31 and 30 thereof are preferably in open communication with thechamber 22 so that the 9 fluid .of the manometric devices shall be subjected to the pressure of gas developed by the blower 12 and the air developed by the the pressure existing in the chamber 22.

The rotors l16 and 17 are identical in construction and it is necessary to describe only one specificallyl Referring to the air blower 13, it will be noted that the casing 15 is provided with bearings 34 having packing 35 1w held in place by caps 36. The outside-cap 36 is connected tothe air supply conduit 21 aligned with the outer end o the shaft 18, the latter'having an axial passage 3 7 communicating with radial passages 38. The l rotor 17 is preferabl made of dished mem- 1 bers 39 and 40 held 1n place on the shaft 18 by means of a shoulder 41 provided on the shaft and by a nut 42 threaded to the shaft,

v `in which afford communication between the passages 38 and the space between the dished members, and a spacing member 46 being arranged between the nut 42 and the dished member 40. The dished members are )oined at their peripheries in any suit-able manner, as indicated at 47, and adjacent to the joint air outlet openings 48 are provided. In operation, air enters the rotor 17 from the supply connection 21; and, due to centrifugal force, such air is discharged from the openings 48, thereby building up air pressure in the casing l5 which depends both upon the speed and they density of air. 16 is identical in structure and acts on gas in the same way.

Since the pressures developed in the gas and air blowers are, respectively, functions of the angular velocity and density, if the rotors have the same angular velocity, the factor of angular velocity cancels out of thve equation for specific gravity,

f(wDa) Da determined or fixed relation of angular velocities, it will be apparent that the rotors might be of different diameters, operate at different angular velocities, or both, so long as the relation is fixed and known; however,

lI prefer, from the standpoint of simplicity,

to have the ratio of the angular velocities equal to unity.

Since specific gravity of a gas is the quotient of the density of gas divided bythe density of air, in order to readily and automatically effect acts of division for this purpose, as more fully disclosed in my application, Serial No. 657,344, led Aug. 14, 1923, I preferably use logarithmic floats 50 and 51 in connection with the fluid in the legs 31 and 32, the design of each fioat being such that the buoyant force thereof is proportional to the logarithm of the liquid level. The floats 50 and 51 are preferably carried by a beam 52 fulcrumed at 53. Considering counterclockwise moments as positive, and clockwise moments as negative, it will be apparent that the logarithm. of the specific gravity of the gas is equal to the moment of the logarithm of the liquid level in leg 31 minus the moment of the logarithm of the liquid level in leg 32. In order to The rotor` readily determine the value of. the density of the las divided by the density of air, I prefera ly associate in connection with the beam 52, a third ioat 54 connected to the beam and arranged within a receptacle,55. The float 54 is designed oppositely in principle to the floats 50 and 51; in other words, the zero orv datum position would fall above the top of thedfioat, so that any increase in the liquid level in the receptacle 55 corresponds to the decrease in the logarithm of the liquid level. Any suit-able liquid may be supplied to the receptacle 55 by a conduit 56 having a valve 57 therein, and liquid may of the liquid level, it will be apparent that thelmoments developed about the fulcrum 53 'will be equal to the logarithm of the liql uid level in the leg 31 times the distance of the support connection of the float 34 from the fulcrum 53. In like manner, a moment will be supplied to the imam 52 corresponding to the logarithm of the liquid level in the leg 32 times the distance of the support of the float 51 from the fulcrum 53. If, in operation, the equilibrium position of the beam 52 is disturbed, owing to a change in the specific gravity of the gas, such beam will move, displacing the pointer 60, carried by the lever, with respect to the stationary pointer or indicator 61, the pointers 60 and 6l being opposite to each other when the beam 52 is in normal position. With a disturbance of the normal position of the beam 52, owing to a change in the specific gravity of the gas, the operator admits or withdraws fluid to or from the receptacle 55 in order that a moment may be applied to the beam for bringing the latter back to normal position with the pointers 60 and 61 in registry. Since the float 54 is of the logarithmic type, but oppositely designed when compared with the ioats 50 and 51, it will be apparent that, in equilibrium position of the beam 52, the

-moment of the buoyant effect of the iioat 54 is equal to the moment of the buoyant effect of the iioat 50 minus that of the float 51.

The receptacle 55 has a gauge glass 63 communlcatlng at the bottom thereof, vthe upper end of the gauge glass being in communication w1th the chamber 22 so that equality of the pressures is assured on the Asurface of liquid in the glam 63 and on the surface of liquid in the reoepte 55. The

iso

refine a conduit 64 which communicates with theoutlet connection 25 and with the main 10, the conduit containing a small orifice 65, so that a small flow or-circulation of gas is assured with the result that a stagnant accumulation in the gas blower is avoided.

While I have shown my invention in but one form, it will be obvious to those skilled in the art that it is not so limited, but is susceptible of various other modifications without departing from the spirit thereof, and I de-sire, therefore, that only such limitations shall be placed thereupon as are imposed by the prior art Oras are Specifically set forth vin the appended claims.

Having thus described the invention what I claim as new and desire to secure by Letters Patent is:

1. In apparatus for determining specific gravity of a gas, first and second pressuredeveloping centrifugal devices, means for operatin said devices in a predetermined speed re ation, means for supplying air to the first device, means for supplying gas to the second device, means for maintaining an equilibrium of pressures of the air and gas 85 supplied to the respective devices, outlet connections for the devices, manometers having legs connected to the respective outlet connections of the devices and havin their other legs subjected to the pressure o the supplied air and gas, oa in said other legs, and means operated by said floats for ascertaininv the specific gravity of the gas 1n terms o air. v

2. In gas specific gravity determining apparatus, the combination of a gas mam, .a blower connected to the gas main, a. manometer connected to the outlet of the blower, and means for securing limited circulation of gas from the main through the blower and back to the main, an air blower, a manometer connected to the outlet thereof, and means responsive to the level derence in said manometers for disclosing the specie gravity of gas in terms of air.

3. In specific gravity determining apparatus, the combination ofa pair of blowers, means for supplying gas to one blower, means for supplyinv air to the other blower, outlet connections ttor the blowers, manometers associated with the respective outlet connections, logarithmic oats in the manometers, and a balance beam for connecting the floats, a receptacle, a logarithmic float in the receptacle, means for supplying or withdrawin luid to or from the receptacle, and

indicating means for showing the liquid level in said receptacle.

In testimony whereof I hereunto ax m signature this 22nd day of May, 1924.

GARRETT B. LINDERMAN, JR. 

